Many diseases require complex health care regimens and affect large numbers of people. For example, congestive heart failure (CHF) is a major health problem and affects over five million people in the United States alone. CHF is the loss of pumping power of the heart, resulting in the inability to deliver enough blood to meet the demands of peripheral tissues. CHF patients typically have enlarged heart with weakened cardiac muscles, resulting in reduced contractility and poor cardiac output of blood.
CHF is usually a chronic condition, but can occur suddenly. It can affect the left heart, right heart or both sides of the heart. If CHF affects the left ventricle, signals that control the left ventricular contraction can be delayed, which can result in the left and right ventricles not contracting simultaneously. Non-simultaneous contractions of the left and right ventricles further decrease the pumping efficiency of the heart.